The melancholy comedy, gaining buzz on the festival trail, hits a hopeful note for the director and his co-writer and star.

Oscar-nominated writer-director Noah Baumbach is known as the creator of literate, personal films about characters in crisis. Actress Greta Gerwig has parlayed her deft touch playing blond oddballs in small indie films into work with an impressive roster of filmmakers including Woody Allen, Ivan Reitman and Whit Stillman.

Now the real-life couple, who worked together on "Greenberg," have co-written a melancholy comedy, "Frances Ha" that's becoming one of the most-buzzed-about films on the fall film festival circuit. Directed by Baumbach, the black-and white movie stars Gerwig as an aspiring dancer in New York City who's thrown off balance when her relationship with her best friend and roommate undergoes a sudden strain.

At first blush, it doesn't sound like much of a departure for either of them, yet the alchemy of their collaboration seems to have brought out something new from both.

"Frances Ha" became the toast of the Telluride Film Festival when it first screened there last week — audiences seemed pleasantly surprised by the warmth from the often-mordant Baumbach, and one reviewer called it "Gerwig's defining performance to date." The film is set to unspool Friday night at the Toronto International Film Festival, where it's one of the most high-profile movies in the market for a distribution deal and will move on the New York Film Festival in late September.

In an interview between Telluride and Toronto, Baumbach said that if the tone of "Frances Ha" feels lighter than his other works, it wasn't totally intentional. "I do really set out thinking each one is a comedy and then whatever happens, happens," he said, adding that he was surprised how hostile some audiences had been to characters in both "Greenberg" and his 2007 movie "Margot at the Wedding."

"I will say about this movie," he added, "I feel like the final product is closer to whatever abstract idea I had in my head when I set out to do it than anything I've done."

Baumbach and Gerwig have been looking to do another project together since he first directed her in 2010's "Greenberg" and then in his unaired pilot for an adaptation of Jonathan Franzen's novel "The Corrections."

They began by informally trading ideas and notes back and forth, then developed those into characters. Finally, they wrote a full-fledged script centering on 27-year-old Frances as she finds herself unprepared for adult life and reeling further when she and her close friend Sophie (played by Mickey Sumner, daughter of Sting and Trudie Styler) have a falling out. They aren't lovers, but there's no question it's a breakup.

With this foray into screenwriting, Gerwig, 29, has become part of a current wave of actresses writing or co-writing their own material, a group that includes Zoe Kazan ("Ruby Sparks") and Rashida Jones ("Celeste and Jesse Forever"). But Gerwig said she didn't necessarily intend to play Frances.

"The writing of it and the acting of it were separate for me," she said by phone while briefly in Los Angeles between Telluride and Toronto. "I did feel like I had to write this script. The writing of it was such a huge thing, but the acting of it was scary. I really was worried I wouldn't be right for it.... It didn't feel like, 'I wrote this great part, and I'm perfect for it.'"

Baumbach admitted he had other ideas. "I can say I totally had Greta in my head," he said. "I always thought, 'I can't wait for Greta to play this part.'"

Baumbach tackled post-college ennui in his 1995 debut feature, "Kicking and Screaming" (that film's star, Josh Hamilton, has a small role in "Frances"), but moved on to explorations of divorce ("The Squid and the Whale"), family dysfunction ("Margot at the Wedding") and adult drift ("Greenberg").

Returning to the subject at age 43, Baumbach acknowledged that he brings a different perspective — or as he joked, "farness" — to that period in one's life. "I could in some ways have the distance of the director: How will I shoot this? What is the best way to tell this story? Probably not being 27 helped me do that in a more efficient way. But I also totally connect to the story."

Baumbach shot "Frances Ha" digitally on what he calls a "modest budget" and opted to make the movie in black and white in part to replicate the look of the collaborations between Woody Allen and cinematographer Gordon Willis on films such as "Manhattan."

The story is divided into chapters according to the addresses where Frances lives as she bounces from place to place in search of a true home and a more complete self. A Christmas sequence was shot in Sacramento (with Gerwig's parents playing Frances' parents), a weekend getaway in Paris and there's also a summer sojourn at Baumbach's alma mater, Vassar. It's all part of the process of Frances letting go and moving on, becoming more completely herself.

"I think one of the things we wanted to achieve at the end of the film was this melancholy joy," Gerwig said. "That feeling was really important for us."

If the early reactions are any indication they seem to have achieved that goal. "I think this holds up with any of my movies," Baumbach said. "The hopefulness in this one was never in question. I always wanted to reward Frances at the end of this movie. The character was hopeful, the process of making it was hopeful. It just felt like the way this movie should be."